Today, many complex structures, such as aircraft, spacecraft, automobiles, and the like, are made from composite materials. Composite materials typically include fibrous materials embedded in a matrix made from thermoset materials. Uncured thermoset materials are arranged in a desired manner and then cured to harden the matrix. Like complex structures made from more traditional materials, such as metal, complex structures made from composite materials include a significantly large number of interconnected components. The interconnected components of complex structures are connected together at joints. The joints of conventional complex structures are traditionally formed using fasteners and weldments. However, the joints of some complex structures formed from composite materials are formed using adhesives and co-curing of thermoset materials.
To improve the characteristics of joints between components made from composite materials, the components incorporate bends at the joints, which introduce gaps within the joints. Often, the gaps are filled with thermoset materials that cure concurrently with the thermoset materials forming the components. Because uncured thermoset materials are flexible and pliable, before and during curing, maintaining such materials in place can be difficult. Additionally, after curing, thermoset joint fillers are susceptible to cracking due to thermal and mechanical static and fatigue loads.